And 7 pairs of what they considered "clean" animals... plus food for a year. (Clean animals were the ones that resisted the change from being domesticated into being wild animals, when all the others became wild after the fall into sin.)

However, consider that all 7.5 billion people in the world today, could fit standing, on 1 square mile of land. Lots more room in the big boat than one might think.

Also, the CO2 from all those animals in the big boat, would keep them all in a near hibernation state, so that they would eat less, and be relaxed enough to be peaceful.

Lots of stuff to consider.